Experimental study of the nucleation of alumina inclusions in liquid steel

Abstract

An experimental setup was constructed to study the nucleation and growth of non‐metallic inclusions in liquid steel. The setup allows easy control of the atmosphere in the reaction chamber as well as fast and smooth movement of the sample. A liquid steel sample can be moved smoothly from the reaction chamber to the quenching zone of room temperature in 2 s. The rapid freezing of the sample enables the study of the formation, growth and distribution of the inclusions. A preliminary study on the homogeneous nucleation of alumina was carried out. Experimental evidence of homogeneous nucleation in the region of aluminium supersaturation was found in the sample quenched 5 s after aluminium addition. Fast agglomeration was also observed. In all the samples quenched 15 s or longer after the aluminium addition, agglomerated alumina clusters were found.